[MCN] Among other things, snowpack decline kindles more severe fire in the western United States

[Lance Olsen]

Snowpack decline kindles more severe fire in the western United States

Jared A Balik*, Jonathan D Coop and Sean A Parks
Published 23 March 2026 • © 2026 The Author(s). Published by IOP Publishing Ltd
Environmental Research Letters <https://iopscience.iop.org/journal/1748-9326>, Volume 21 <https://iopscience.iop.org/volume/1748-9326/21>, Number 6 <https://iopscience.iop.org/issue/1748-9326/21/6>
Citation Jared A Balik et al 2026 Environ. Res. Lett. 21 064010
DOI 10.1088/1748-9326/ae4e4a
Article PDF <https://iopscience.iop.org/article/10.1088/1748-9326/ae4e4a/pdf>
2239 Total downloads
Abstract

Climate change is reducing winter snowpack and advancing spring snowmelt across the western United States, interacting with El Niño–Southern Oscillation (ENSO) teleconnections that drive spatially predictable interannual fluctuations that contribute to high- or low-snow winters. Early snowmelt extends the fire season, enhancing opportunities for ignition and increasing fuel dryness, both of which contribute to greater burned areas. However, relationships between snowpack on burn severity, a measure of forest loss and expected biogeochemical and hydrological impacts of fire, have not been examined. Here, using remotely sensed snow and fire data spanning 1985–2021, we examined how snowpack quantity and timing of spring snowmelt influence annual area burned and burn severity at the watershed scale. Early snowmelt was associated with earlier occurrences of fire ⩾400 ha and greater annual area burned, whereas low snowpack water content was associated with more severe burn outcomes including greater mean composite burn index (CBI) and larger proportions of high severity fire (CBI ⩾ 2.25). Thus, low-snow winters with early snowmelt may prime forested watersheds to dry, burn, and experience high severity fire. These outcomes are consistent with enhanced fuel dry-down: early snowmelt extends the dry-down window while low snowpack quantity portends greater fuel aridity during the dry period. Our findings also highlight how the ENSO interacts with directional warming: El Niño phases amplify trends of snowpack loss and increasing area burned severely in northwestern watersheds but dampen these trends in southwestern watersheds, while La Niña phases exert the opposite effect. Projected warming, potentially accompanied by greater ENSO variability and extremes, points toward a future of reduced snowpack, earlier snowmelt, and increased area burned at high severity in forests where snowpack historically buffered fire risk, with attendant losses in forest carbon storage and disrupted hydrological function of forested watersheds.



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2002 - “Although we are only at an early stage in the projected trends of global warming, ecological responses to recent climate change are already clearly visible.”

Walther et al, “Ecological responses to recent climate change.” Nature, March 28, 2002
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2006 - “Climate change is not a new topic in biology...... Observations of range shifts in parallel with climate change ... date back to the mid-1700s.”

“This review  …  deals exclusively with observed responses of wild biological species and systems ….  “

"A surprising result is the high proportion of species responding to recent, relatively mild climate change (global average warming of 0.6 C)." 

Parmesan, Camille. Ecological and Evolutionary Responses to Recent Climate Change. The Annual Review of Ecology, Evolution, and Systematics  37: pp. 637-69. 2006.

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